A group of children get the thrill of a lifetime when they decide to cut short their walk home in Crews's new picture book. Though they know the freight train might round the bend momentarily, the kids opt for playing along the tracks instead of walking on their familiar route. Charged with excitement, the escapade turns to fullblown alarm when the train whistle sounds, sending the youngsters scrambling to safety at the last minute. Crews's economical text deftly explores a roller coaster ride of emotion in just a few paragraphs, highlighted with effective onomotopeia-Whoo wh(,o; klackity, klackity, klack. The underlying childlike sensibilities here-taking a risk to the limit, for example-authenticate the author's voice throughout. The story, an extension of the characters first introduced in Crews's nostalgic Bigmama's, is a perfect foil for the artist's masterful renderings of trains. A predominantly warm, earthy palette sets a serene and playful mood at the outset, followed by several dark, wordless spreads that show freight cars rushing past, ready to speed right off the page. Scenes portraying the frightened children are equally effective in this out of the ordinary drama set forth with uncommon artistry. Ages 4-up. (Oct.)